PT Journal
AU Bell, M
   Sergeev, A
   Mitin, V
   Bird, J
   Verevkin, A
   Gol'tsman, G
TI One-dimensional resistive states in quasi-two-dimensional superconductors
SO arXiv:0709.0709v1 [cond-mat.supr-con]
PY 2007
BP 1
EP 11
AB We investigate competition between one- and two-dimensional topological excitations - phase slips and vortices - in formation of resistive states in quasi-two-dimensional superconductors in a wide temperature range below the mean-field transition temperature T(C0). The widths w = 100 nm of our ultrathin NbN samples is substantially larger than the Ginzburg-Landau coherence length ξ = 4nm and the fluctuation resistivity above T(C0) has a two-dimensional character. However, our data shows that the resistivity below T(C0) is produced by one-dimensional excitations, - thermally activated phase slip strips (PSSs) overlapping the sample cross-section. We also determine the scaling phase diagram, which shows that even in wider samples the PSS contribution dominates over vortices in a substantial region of current/temperature variations. Measuring the resistivity within seven orders of magnitude, we find that the quantum phase slips can only be essential below this level.
ER